Note the appearance of Canadian and US flags alongside each other. It was an essential plot element of the movie, but accidentally honors the co-creators of Superman.
The most unique flag explaining the 'Superman' Icon appears in the metallic virtua-chamber in the ancient yet advanced ship from Krypton. Man of Steel digs deep in the American psyche and confronts face first the horrors of 9/11, patriotism, paranoia, and fear. In the end, the theme of hope is presented as a universal force within the human race, allowing Superman to become a symbol and luminous beacon, radiating hope for the people of earth to follow.